Bender MRCDB300 Series User manual

Manual
EN
MRCDB300 series
AC/DC sensitive residual current monitoring module
for MRCD applications
MRCDB300-series_D00343_03_M_XXEN/07.2020 MANUAL EN

Bender GmbH & Co. KG
Postfach 1161 • 35301 Grünberg • Germany
Londorfer Str. 65 • 35305 Grünberg • Germany
Tel.: [phone] • Fax: [phone]
E-Mail: [e-mail] • www.bender.de
©Bender GmbH & Co. KG
Alle Rechte vorbehalten.
Nachdruck nur mit Genehmigung des Herausgebers.
Änderungen vorbehalten!
Fotos: Bender Archiv

3
Table of Contents
MRCDB300-series_D00343_03_M_XXEN/07.2020
1. General instructions ............................................................................... 7
1.1 How to use this manual .................................................................................. 7
1.2 Technical support: service and support .................................................... 7
1.3 Training courses ................................................................................................. 8
1.4 Delivery conditions ........................................................................................... 9
1.5 Inspection, transport and storage ............................................................... 9
1.6 Warranty and liability ....................................................................................... 9
1.7 Disposal ............................................................................................................... 10
2. Safety instructions ............................................................................... 11
2.1 General safety instructions .......................................................................... 11
2.2 Work activities on electrical installations ................................................ 11
2.3 Intended use ..................................................................................................... 11
3. Device description ............................................................................... 13
3.1 Area of application .......................................................................................... 13
3.2 Device features ................................................................................................. 13
3.3 Variants ............................................................................................................... 14
3.4 Functional description ................................................................................... 15
3.4.1 Delay times tb, t, ton, and toff .................................................................... 16
4. Installation and connection ............................................................... 17
4.1 Composition of an MRCD module ............................................................ 17
4.2 Installing the device ....................................................................................... 18
4.2.1 Dimension diagrams ...................................................................................... 18
4.2.2 Mountings .......................................................................................................... 19
4.3 Assembly ............................................................................................................ 19
4.4 Connecting the device .................................................................................. 20
4.4.1 Device view MRCDB30… .............................................................................. 20
4.5 Wiring diagrams ............................................................................................... 21
4.5.1 N/C principle without contact feedback ................................................. 21
4.5.2 N/C principle with contact feedback ........................................................ 22
4.5.3 N/O principle without contact feedback ................................................ 23
4.5.4 N/O principle with contact feedback ....................................................... 24

Table of Contents
4MRCDB300-series_D00343_03_M_XXEN/07.2020
4.6 Connection RS-485 interface (Modbus RTU) ......................................... 25
4.7 Installation instructions for measuring current transformers ......... 25
4.7.1 Protective conductors and live conductors ........................................... 26
4.7.2 Bending cables ................................................................................................. 26
4.7.3 Routing cables centrally ................................................................................ 26
5. Commissioning ...................................................................................... 27
5.1 Setting addresses ............................................................................................ 27
5.2 Offset calibration ............................................................................................. 29
5.3 Completing and checking installation ..................................................... 30
6. Test, reset, function test ...................................................................... 31
6.1 Periodic self test ............................................................................................... 31
6.2 Manual self test ................................................................................................ 31
6.2.1 Integrated "T" button ..................................................................................... 31
6.2.2 External test/reset button ............................................................................ 31
6.3 Function test ..................................................................................................... 32
7. Modbus register .................................................................................... 33
7.1 Overview ............................................................................................................. 33
7.1.1 Read and write accesses ............................................................................... 33
7.1.2 Formats used ..................................................................................................... 33
7.1.3 Register areas .................................................................................................... 34
7.1.4 Representation of values .............................................................................. 34
7.1.5 Alarm assignments ........................................................................................ 35
7.1.6 Descriptions ....................................................................................................... 35
7.2 Device information ......................................................................................... 35
7.3 Detailed measured values ............................................................................ 37
7.4 General measured values ............................................................................. 38
7.4.1 Error codes ........................................................................................................ 39
7.5 History .................................................................................................................. 41
7.6 Device parameters and factory settings ................................................. 42
7.7 Control commands ......................................................................................... 47
7.8 Additional function codes: ........................................................................... 48
7.8.1 Diagnostic (function code 0x08) ................................................................ 48
7.8.2 Get Com Event Counter (function code 0x0B) ...................................... 49
7.8.3 Report Server ID (function code 0x11) ..................................................... 49
7.8.4 Device Identification (function code 0x2B) ............................................ 49

Table of Contents
5
MRCDB300-series_D00343_03_M_XXEN/07.2020
8. System states: LED and output relays ............................................. 51
9. Frequency responses ........................................................................... 53
9.1 Low passes LP ................................................................................................... 53
9.2 Type B+ ............................................................................................................... 53
9.3 Type B .................................................................................................................. 54
9.4 Fire protection 100 kHz ................................................................................. 54
10. Technical data ..................................................................................... 55
10.1 Tabular data ....................................................................................................... 55
10.2 Standards and certifications ........................................................................ 59
10.3 Ordering details ............................................................................................... 59
10.3.1 Electronic modules ......................................................................................... 59
10.3.2 Measuring current transformers ................................................................ 60
10.3.3 Accessories ........................................................................................................ 60
10.3.4 Suitable system components ...................................................................... 60
INDEX ........................................................................................................... 61

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MRCDB300-series_D00343_03_M_XXEN/07.2020
1. General instructions
1.1 How to use this manual
Always keep this manual within easy reach for future reference. We have used the fol-
lowing symbols to identify important instructions and information:
1.2 Technical support: service and support
For commissioning and troubleshooting Bender offers:
First level support
Technical support by phone or e-mail for all Bender products
•Questions about specific customer applications
•Commissioning
•Troubleshooting
Telephone: [phone]*
Fax: [phone]:-259 Germany: 0700BenderHelp (telephone and fax)
E-mail: [e-mail]
This manual is intended for qualified personnel working in electrical
engineering and electronics!
This signal word indicates that there is a high risk of danger that will
result in death or serious injury if not avoided.
This signal word indicates a medium risk of danger that can lead to
death or serious injury, if not avoided.
This signal word indicates a low-level risk that can result in minor or
moderate injury or damage to property if not avoided.
This symbol denotes information intended to assist the user in making
optimum use of the product.
DANGER
WARNING
CAUTION

General instructions
8MRCDB300-series_D00343_03_M_XXEN/07.2020
Repair service
Repair, calibration, update and replacement service for all Bender products
•Repair, calibration, testing and analysis
•Hardware and software update
•Delivery of replacement devices for faulty or incorrectly delivered devices
•Extended warranty with in-house repair service or replacement device at no extra
cost
Telephone: [phone]** (technical issues)/
[phone]**, -785** (commercial issues)
Fax: [phone]
E-mail: [email protected]
Please send the devices for repair to the following address:
Bender GmbH, Repair-Service, Londorfer Straße 65, 35305 Grünberg
Field service
On-site service for all Bender products
•Commissioning, parameter setting, maintenance, troubleshooting
•Analysis of the electrical installation in the building (power quality test, EMC test,
thermography)
•Practical training courses for customers
Telephone: [phone]**, -762 ** (technical issues)/
[phone]** (commercial issues)
Fax: [phone]
E-mail: [email protected]
Internet:www.bender.de
*Available from 7.00 a.m. to 8.00 p.m. on 365 days of the year (CET/UTC +1)
**Mo-Thu 7.00 a.m. - 4.00 p.m., Fr 7.00 a.m. - 1.00 p.m
1.3 Training courses
Bender is happy to provide training regarding the use of test equipment.
The dates of training courses and workshops can be found on the Internet at
www.bender.de -> Know-how -> Seminars.

General instructions
9
MRCDB300-series_D00343_03_M_XXEN/07.2020
1.4 Delivery conditions
The conditions of sale and delivery set out by Bender apply.
For software products, the "Softwareklausel zur Überlassung von Standard- Software
als Teil von Lieferungen, Ergänzung und Änderung der Allgemeinen Lieferbedingun-
gen für Erzeugnisse und Leistungen der Elektroindustrie" (software clause in respect of
the licensing of standard software as part of deliveries, modifications and changes to
general delivery conditions for products and services in the electrical industry) set out
by the ZVEI (Zentralverband Elektrotechnik- und Elektronikindustrie e.V., (German Elec-
trical and Electronic Manufacturers' Association) also applies.
Conditions of sale and delivery can be obtained from Bender in printed or electronic for-
mat.
1.5 Inspection, transport and storage
Inspect the dispatch and equipment packaging for damage, and compare the contents
of the package with the delivery documents. In the event of damage in transit, please
contact Bender immediately.
The devices must only be stored in areas where it is protected from dust, humidity and
spray or dripping water, and in which the specified storage temperatures can be as-
sured.
1.6 Warranty and liability
Warranty and liability claims in the event of injury to persons or damage to property are
excluded if they can be attributed to one or more of the following causes:
•Improper use of the device.
•Incorrect mounting, commissioning, operation and maintenance of the device.
•Failure to observe the instructions in this operating manual regarding transport,
commissioning, operation and maintenance of the device.
•Unauthorised changes to the device made by parties other than the manufacturer.
•Non-observance of technical data.
•Repairs carried out incorrectly and the use of replacement parts or accessories not
approved by the manufacturer.
•Catastrophes caused by external influences and force majeure.
•Mounting and installation with device combinations not recommended by the man-
ufacturer.
This operating manual, especially the safety instructions, must be observed by all per-
sonnel working on the device. Furthermore, the rules and regulations that apply for ac-
cident prevention at the place of use must be observed.

General instructions
10 MRCDB300-series_D00343_03_M_XXEN/07.2020
1.7 Disposal
Abide by the national regulations and laws governing the disposal of this device. Ask
your supplier if you are not sure how to dispose of the old equipment.
The directive on waste electrical and electronic equipment (WEEE directive) and the di-
rective on the restriction of certain hazardous substances in electrical and electronic
equipment (RoHS directive) apply in the European Community. In Germany, these pol-
icies are implemented through the "Electrical and Electronic Equipment Act" (ElektroG).
According to this, the following applies:
•Electric and electronic equipment are not to be included in household waste.
•Batteries and accumulators are not to be included in household waste but must be
disposed of in accordance with the regulations.
•Old electrical and electronic equipment from users other than private households
which was introduced to the market after 13 August 2005 must be taken back by the
manufacturer and disposed of properly.
For more information on the disposal of Bender devices, refer to our website at
www.bender.de -> Service & support.

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MRCDB300-series_D00343_03_M_XXEN/07.2020
2. Safety instructions
2.1 General safety instructions
Part of the device documentation in addition to this manual is the enclosed " Safety in-
structions for Bender products".
2.2 Work activities on electrical installations
If the device is used outside the Federal Republic of Germany, the applicable local
standards and regulations must be complied with. The European standard EN 50110
can be used as a guide.
2.3 Intended use
The AC/DC sensitive residual current monitors of type MRCDB30… are used in combi-
nation with a CTBC… measuring currentt transformer and a circuit breaker according
to IEC 60947-2 as additional protection in industrial power supplies. According to IEC
60364-5-53, the use in earthed power supplies (TN and TT systems) up to 800 V is pos-
sible. These devices are suitable for monitoring AC and DC fault currents (type B).
Any other use than that described in this document is regarded as improper.
Only qualified personnel working in electrical engineering and
electronics are permitted to carry out the work necessary to install,
commission and run a device or system.
Risk of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
•An electric shock
•Damage to the electrical installation
•Destruction of the device
Before installing and connecting the device, make sure that the
installation has been de-energised. Observe the rules for working on
electrical installations.
Refer to the rated and supply voltage values as specified in the techni-
cal data!
DANGER

12
MRCDB300-series_D00343_03_M_XXEN/07.2020
3. Device description
3.1 Area of application
The AC/DC sensitive device series MRCDB30… is used in combination with a CTBC… as
additional protection (protection against indirect contact) in earthed systems (TN and
TT systems) in which AC or DC fault currents may occur.
Part of these systems are particularly loads containing six-pulse rectifiers or one-way
rectifiers with smoothing, such as converters, battery chargers, construction site equip-
ment with frequency-controlled drives. When the response value IΔn1 (prewarning) is
reached, the output relay K1 switches. When the response value IΔn2 (alarm) is reached,
the output relay K2 also switches.
By using an MRCDB30… module and a switching element with isolating properties, the
device combination fulfils the requirements of IEC 60947-2 Annex M for an MRCD pro-
tective device.
The application is specifically intended for protection goals such as protection of per-
sons, fire protection and plant protection. The switching element must not exceed a
switch-off time of 20 ms.
The CTBC…Pseries measuring current transformers feature an integrated magnetic
shield and are suitable for applications with high load currents or inrush currents.
3.2 Device features
•Structure of a protective device in accordance with IEC 60947-2 Annex M in combi-
nation with a circuit breaker providing isolating properties
•Monitoring of the connected circuit breaker by means of contact feedback
•RS-485 interface with Modbus RTU (reading out measured values/setting parame-
ters)
•Integrated switching outputs with two changeover contacts K1 and K2 (galvanically
isolated)
•Fulfils the protection goals protection of persons, fire protection and plant protec-
tion (depending on the variant)
•Frequency range (depending on the variant) DC…100 kHz
•Combined test and reset button
•Multicolour LED indicating operation, exceeded response value, disturbances and
status messages
•AC/DC sensitive type B measured value acquisition acc. to IEC 60755 (depending on
the variant)

Device description
13 MRCDB300-series_D00343_03_M_XXEN/07.2020
•AC/DC sensitive type B+ measured value acquisition acc. to VDE 0664-400 (depend-
ing on variant)
•Exchangeable electronic enclosure without mechanical separation of the primary
conductors
•Extension/retrofitting or modification of functionalities in case of changed monitor-
ing requirements
•Insensitive to load currents due to full magnetic shield (CTBC…Ponly)
•Connection monitoring of the measuring current transformer with cyclical test cur-
rent
•Use of all MRCDB30… for all CTBC… measuring current transformer sizes
•Supply voltage DC 24 V
3.3 Variants
Electronic modules
•MRCDB301
Type B modular residual current protective device acc. to IEC 60755 for the protec-
tion of persons in case of indirect contact, response value 30 mA
•MRCDB302
Type B+ modular residual current protective device acc. to VDE 0664-100 for fire
protection, response value 300 mA
•MRCDB303
Modular residual current protective device for plant protection
(N/C operation), freely configurable
•MRCDB304 (only on request)
Modular residual current protective device for plant protection
(N/O operation), freely configurable
•MRCDB305
Modular residual current protective device type B acc. to IEC 60755 for the protec-
tion of persons in case of indirect contact; for applications with pulse-shaped, very
high peak load currents (> 1 kA for < 1 s), e.g. welding applications, response value
30 mA
Measuring current transformers (P = shielded)
•CTBC20(P) Measuring current transformer, internal diameter 20 mm
•CTBC35(P) Measuring current transformer, internal diameter 35 mm
•CTBC60(P) Measuring current transformer, internal diameter 60 mm
•CTBC120(P) Measuring current transformer, internal diameter 120 mm
•CTBC210(P) Measuring current transformer, internal diameter 210 mm

Device description
14
MRCDB300-series_D00343_03_M_XXEN/07.2020
3.4 Functional description
Residual current IΔn
The residual current monitoring module measures both AC and DC currents. Tripping
takes place based on the determined r.m.s. value. When the response value set for IΔn2
(alarm) is exceeded by a residual current, the output relay K2 switches an undervoltage
release (recommended) or a shunt release (N/O operation) within the required tripping
time and the LED lights up red.
If the fault memory behaviour of relay K1 or K2 is activated, the device must be reset by
pressing the "T" button.
The MRCD module automatically checks the measuring current transformer and the
function of the residual current measurement cyclically.
Offset calibration
When the device has been installed, an offset calibration should first be carried out (see
page 29). After successful offset calibration, the multicolour LED lights up green and the
device is ready for operation.
Test
Press the "T" button or the external test button for 5…10 s to start the manual self test
of the device.
Reset
Press the "T" button or the external test button for 1.5...5 s to reset the device.
Contact feedback
The contact feedback ensures that the circuit breaker is in the desired switching state.
RS-485 interface
The RS-485 interface enables both reading out the measured values and setting the pa-
rameters of the device via Modbus RTU. Furthermore, a test or a reset can be triggered
via the bus.
Switch-off control (MRCDB3… only)
After an alarm, the measured IΔ(r.m.s.) must be lower than 0.5 x IΔn of the smallest alarm
limit value active via alarm assignment, so that K2 switches on again. If the residual cur-
rent is permanently higher, this is a sign of a welded contactor or incorrect wiring. The
device displays an error (error code: 0.56).

Device description
15 MRCDB300-series_D00343_03_M_XXEN/07.2020
3.4.1 Delay times tb, t, ton, and toff
The times tb, t, ton and toff described below delay the output of alarms via LEDs, relays
and Modbus RTU.
Recovery time tb
The recovery time is the time the device needs to be ready for measurement after con-
necting the supply voltage Us.
Start-up delay t
After connecting the supply voltage Us, the measuring function is delayed by the set
time t(0…999 s) plus the recovery time tb.
Response delay ton
If a residual operating current is exceeded, the residual current monitor requires the re-
sponse time tan to output the alarm. A set response delay ton (0…10 s) is added to the
device-specific operating time tae and delays signalling:
Response time tan = tae + ton
If the fault does not persist during the response delay, the alarm is not signalled.
Delay on release toff
If the alarm no longer exists and the fault memory is disabled, the alarm LEDs go out and
the alarm relays switch back to their initial position. By means of the delay on release
(0...999 s), the alarm state is maintained for the selected period.

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MRCDB300-series_D00343_03_M_XXEN/07.2020
4. Installation and connection
4.1 Composition of an MRCD module
Any combination of electronic modules (MRCDB30…) and measuring current trans-
formers (CTBC…) is possible to enable individual adaptation to every installation situa-
tion.
Only qualified personnel working in electrical engineering and
electronics are permitted to carry out the work necessary to install,
commission and run a device or system.
Risk of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
•An electric shock
•Damage to the electrical installation
•Destruction of the device
Before installing and connecting the device, make sure that the
installation has been de-energised. Observe the rules for working on
electrical installations.
Refer to the rated and supply voltage values as specified in the
technical data!
DANGER

Installation and connection
17 MRCDB300-series_D00343_03_M_XXEN/07.2020
4.2 Installing the device
4.2.1 Dimension diagrams
Fig. 4.1: Dimension diagrams CTBC… and MRCDB30…
All dimensions in mm, tolerance ±0.5 mm
CTBC20(P)/CTBC35(P) CTBC60(P)
CTBC120(P)/CTBC210(P) MRCDB30…
Type a b c d e f g
MRCDB3…-CTBC20(P) 81 112 37 ø 20 46 60
MRCDB3…-CTBC35(P) 97 130 47 ø 35 46 61
MRCDB3…-CTBC60(P) 126 158 57 ø 60 56 78
MRCDB3…-CTBC120(P) 188 232 96 ø 120 65 96 139
MRCDB3…-CTBC210(P) 302 346 153 ø 210 67 113 277
MRCDB30x 74 37 44 24.6
d
b
f
c
ae
d
e
f
c
b
a
g
a
d
e
c
f
b
c
b
d
a

Installation and connection
18
MRCDB300-series_D00343_03_M_XXEN/07.2020
4.2.2 Mountings
all dimensions in mm, tolerance ±0.5 mm
4.3 Assembly
Fig. 4.2: Assembly electronic module
Steps
1. Place the electronic module on the mark on the measuring current transformer.
2. Fold the electronic module down onto the measuring current transformer.
3. Slide the electronic module onto the plug contacts of the measuring current
transformer.
CTBC20(P)/CTBC35(P) CTBC60(P) CTBC120(P)/CTBC210(P)
Type a b c
CTBC20(P) 31.4 49 2 x ø 5.5
CTBC35(P) 49.8 49 2 x ø 5.5
CTBC60(P) 56 66 2 x ø 6.5
CTBC120 103 81 4 x ø 6.5
CTBC210 180 98 4 x ø 5.5
a
b
c
a
b
c
a
b
c
3
1
2

Installation and connection
19 MRCDB300-series_D00343_03_M_XXEN/07.2020
4.4 Connecting the device
4.4.1 Device view MRCDB30…
Tab. 4.1: Device view MRCDB30…
Risk of electrocution due to electric shock!
Touching live parts of the system carries the risk of:
•An electric shock
•Damage to the electrical installation
•Destruction of the device
Before installing and connecting the device, make sure that the
installation has been de-energised. Observe the rules for working
on electrical installations.
Refer to the rated and supply voltage values as specified in the
technical data!
No. Terminal Meaning
124 V Supply voltage US
2GND
3D1 Contact feedback
4DG
5T/R Connection external test/reset
6GND
7ARS-485 interface
8B
9X1 Terminals for cable bridge for connection of
the integrated terminating resistor of the RS-
485 interface
10 X2
11 11, 12, 14 Relay K1 (prewarning)
12 21, 22, 24 Relay K2 (alarm)
13 –Combined LED
refer to "System states" section
14 – Test and reset button "T"
DANGER
21 22 2411 12 14
K1 K2
34789
125610
11 12
11 12
13 14

Installation and connection
20
MRCDB300-series_D00343_03_M_XXEN/07.2020
4.5 Wiring diagrams
The following applies to all wiring diagrams:
•The use of a type 2 surge protection device (SPD) is mandatory due to possible
impulse voltages and in order to comply with normative requirements.
•The surge protection device must be connected upstream of the power supply unit
on the supply side.
•Features of the surge protection device:
– Nominal discharge current In(8/20 μs): 20 kA
– Response time: 25 ns
– Two-stage: 1 varistor + 1 spark gab
Alternatively, the power supply unit can be connected to a CAT II supply without a
surge protection device.
4.5.1 N/C principle without contact feedback
Fig. 4.3: Wiring diagram MRCDB30…(N/C principle, without contact feedback)
U<
F 6 A
L1
L2
L3
N
DC 24 V
AC
DC
21
GND
T/R
GND
24 V
22 24
21
22 24
11
12 14
3
MRCDB30...-CTBC...
*
Alarm
* surge protection device
Prewarning